1. Field of the Invention
The present invention relates to a casting core for making caliper castings for disc brakes by a metal casting process, and a method of making the caliper castings using the casting core.
2. Description of Related Art
Caliper castings as a starting material for making calipers for use in disc brakes are provided with a cylinder section, a disc pass section and a teeth section. The cylinder section is a cylindrical tube with a bottom section, and is provided with a hole section of a certain depth. The disc pass section extends outwardly approximately along the hole axis from the opening side of the hole section. The teeth section extends from the side of the disc pass section opposite to the cylinder section to the location facing the opening of the hole section of the cylinder section.
The caliper casting is made by placing a core in a mold for casting of molten FCD metal (spheroidal graphite cast iron), and when the molten metal is solidified, the resulting caliper casting is removed by breaking the core. The process therefore requires one core for making one caliper casting.
The core is provided with an axial section on one side thereof for making the hole section, and on the opposite side thereof, there is provided a depression section for making the teeth section, at about right angles to the axis of the axial section, and an internal surface forming section for forming the internal surfaces of the disc pass section disposed on the external section between the depression section and the axial section.
The conventional process for making the caliper castings presented a problem of high cost of production caused by the need to provide one core for each caliper casting.